The project combines clinical, academic and research training leading to an M.S. degree in Endodontics and a Ph.D. degree in Microbiology and Immunology. All requirements of both programs as stated by the Rackham School of Graduate Studies are being completed. The main focus of the research portion of this grant is to study how bacteria which are found in dental plaque interact and attach to tooth surfaces. The bacterial composition of dental plaque may cause dental infections such as caries or periodontal disease. Streptococci are early plaque formers, the first bacteria which attach to the tooth surface. Effects of various sugars, as are found in the human diet, on the metabolism of oral streptococci and their subsequent ability to attach to hydroxyapatite, an in vitro model for the tooth surface, are being studied. As plaque builds up the early colonizers may select for additional plaque organisms which are associated with health or disease. Thus it is important to fully understand these early colony formers. It is hoped that by studying basic interactions between plaque bacteria and their environment, factors which control the composition of dental plaque can be better understood and potentially implemented in the development of biologically based therapeutic regimens for dental diseases.